HYDROZOA — RITCHIE. 831 



Cryptolaria conferta 1, Hartlaub, Res. Voyage S.Y. " Belgica," 

 1897-99, Zool , Hydroiden, 1904, p. 13, pi. ii., fig. 1 (see 

 above under Cryptolaria conferta). 



Station 48. 



A poor colony, 6 cms, high, with strong stem, and few branches 

 arranged in approximately pinnate fashion, is the more typical 

 representative of this species. The varietal name indicates, how- 

 ever, the existence of two distinct growth forncis assumed by the 

 colonies. 



Form 1. Trophosome. — The habit of this form is more robust 

 than that of the type of Cryptolaria crassicaulis, the hydrothecse 

 a|)]>earing larger even to the naked eye, and the ultimate branches 

 less slender and flaccid. The hydrothecse are distichous, 

 regularly alternate, and close-set, the base of one lying on a level 

 with the point where its predecessor becomes free. They are 

 long and of large calibre, adnate for rather more than half their 

 total length. Cylindrical for the greater part, they narrow 

 markedly towards the base, the diameter of which is generally 

 less than one-tliird that of the aperture ; yet the average diameter 

 of the adnate portion is much greater than that of the axial tube 

 at the same level. The hydrotheca-cavity passes without inter- 

 ruption into that of the axial tube, and a smaller perforation 

 situated alongside the base of the hydrotheca gives passage to a 

 strand of ccenosarc passing between the latter and the associated 

 peripheral tube. The hydrothecse curve gradually outwards, the 

 apertures facing outwards and slightly upwards, while the profile 

 of the axial tube follows the curved adcauline outline of the 

 hydrotheca. 



Form 2. Trophosome. — The hydrothecse in the known species 

 of Cryptolaria arise from an axial tube which is, for the most 

 part, surrounded by peripheral tubes, and to this tube they are 

 adnate for the greater portion of their length — except in some 

 cases, wliere, under the peripheral tubes, they are free. In some 

 unusual specimens before me, the axial tube, unencumbered by 

 accessory tubes, has grown along a G emmelaria-\\^e polyzoon ; 

 and, while giving rise in places to normal Cryptolaria branches, 

 more frequently bears solitary, free hydrothecce which were at 

 first mistaken for examples approaching the smooth variety of 

 Hebella striata, Allman. These hydrothecse grow at right angles 

 to the creeping stolon-like tube, and are almost straight, the 

 marked curve of the adnate hydrothecse being entirely lost. In 

 this state, tiie narrowed base of the adnate hydrotheca is repre- 

 sented by a short peduncle supporting the free one. But except 

 for the straightening, the shape of the two types of hydrotheca 

 is similar, as are their dimensions and proportions. 



